Academic working paper
Ghent University, Faculty of Economics and Business Administration · Working Paper 26/1134 · 2026
RePEc handle: RePEc:rug:rugwps:26/1134
Full paper
Authors
Mathias Celis, Kris Boudt, Mona Bassleer, Wouter Duyck, Stijn Schelfhout, and Nicolas Dirix.
Abstract
In an online vignette study involving 15,593 participants, the authors investigated whether defaults, pre-commitment strategies, evaluative labels, social norms, and combinations of these interventions affected annuity uptake within an occupational pension scheme. Participants allocated pension funds between a lump sum and an annuity using a continuous slider rather than a binary choice.
Pre-commitment produced a small but statistically significant increase in annuitization. Defaults, social norms, evaluative labels, and their combinations produced no significant effects. A stable decision pattern appeared across conditions: 51.2% allocated less than 5% to an annuity, 34.5% selected a mixed allocation, and 14.3% allocated more than 95% to an annuity. Exactly 13% chose a 50/50 split.
The clustering at 0%, 50%, and 100% points to round-number bias on the continuous scale. More broadly, the results show the limits of nudging when decisions are financially complex and shaped by established preferences.
Key findings
- Sample: 15,593 participants.
- Only reliable intervention effect: pre-commitment, small in magnitude.
- No significant effect: defaults, social norms, evaluative labels, or their combinations.
- Dominant choice: less than 5% annuitization, selected by 51.2%.
- Mixed allocation: 34.5%, including a pronounced 13% peak at exactly 50/50.
- Near-full annuitization: 14.3% selected more than 95%.
- Interpretation: salient round numbers and deeply rooted preferences constrained the interventions’ influence.
Suggested citation
Celis, M., Boudt, K., Bassleer, M., Duyck, W., Schelfhout, S., & Dirix, N. (2026). Annuity vs. Lump Sum: A megastudy on occupational pension uptake decisions. Working Papers of the Faculty of Economics and Business Administration, Ghent University, 26/1134.
Sources: IDEAS/RePEc record · Publisher PDF